Key embodying a signaling device



April 17, 1945. -G HOENGER 2,373,893

KEY EMBODYING SIGNALING DEVICES Filed Dec. 23, 1943 Patented Apr. 17,1945 Y Application December 23, 1943,. 5eriall5lo. 515,451 j InSwitzerland Nv einber 4 -194 2I T 4 Claims. (cum-395.)

This invention relates to, alock with a key and embodies a signalingdevice for indicating ifthe key-has-beemused recently for openingor-locking said lock. F 4 a 2' rIngthe devices heretofore proposedwiththe view to meet this requirement, the, key is generallyequippedwith a ring surrounding'the bit, holder; of the key. When operating thislatter in the lock, this-ring is automatically subjected tozaniangulardisplacement Witlrrespect to-the bit, 'r'which displacement indicateswhether a v the key --:has recently been used for opening or'forlocking-theilock. This arrangement maybe suite. azblefor. keys thebitholder of which has a :cir.-. cular section, but the addition of suchaxring to flat'keysLof the kind denominated safetykeys, isdisadvantageous because itdep-rives the keys of the benefit of theirfiat form. a -'-I'he present invention provides a lock with a keyembodying a signaling deviceindicating the actual position-o'fthe boltwhen takingit off,

wherein the signaling device is constituted by at least one element bornbythe key and: movable in ap'lane parallel to the rotation axis .dfithis" Fig. 1 is a front view of a flat key fully inserted within acylinder lock.

slightly smallergthanithe diameterfoi thecircular openings' l5 Withinthe thickness of the key there is a recess 22 closedbyja cover 23.]The-key and the cover are each providedwith circular windows 24 and'iijlocatedv opposite each other Moreover the bottom of the recess 22base blind .,Withi n themes}: all is located the signalingdeyicenThis-latter is-constituted by a springsteelcrankeleverdlpivoted on a.fixe-d pin;'2;8. Qneqof its. arms projects outside of the key; at theregion of its intermediary part 2 I The other arm 30 bears a stampedboss 3| in-.

'7 tended to penetrate either into the .window 24 or into the blind hole25, and -tolock the lever 27 I in a one of the: extreme positions asindicated in fulliand-in chain :dotted lines (see Fig. 2).

- The signaling device operates as follows: a I Theukeyean only-be.introduced into the lock inwthe -position asshown in the drawing that isbymsingthenot'ch l6 for the passage of the bit.

The key. can .onlyrevolve in the-lock after it has Fig. 2 is alongitudinal cross section according v to IIII of Fig. 1.

Fig. 3 is a. longitudinal sectional view accordingfto III-III of Fig. 1.

The embodiment represented is intended fora fiat key for operating acylinder lock revolving about an axis ll, I

Only the parts of the lock necessary for the understanding of theworking of the signaling device showing the actual position of the boltwhen taking off the key, are represented in the drawing;

The lock embodies a drum l2, 2. front-plate I3 I been fully introduced;that is, when. the active or control pa'rtof the-'Ibit has overreachedtheaplane be turned a complete revolution in the right hand direction(seen in front) for locking the lock, then the lateral edges oftheextremity of the arm 29 will successively meet the boss I8, and thenthe boss 11. This latter will push the arm 29 towards the back, with theeffect of bringing the lever 21 into the position indicated in fulllines on Fig. 2. Should now the key be taken out of the lock, then thislatter is in its locked position and the arm 30 of the lever obstructsthe windows'fl and 25, thus indicating that the key has last been usedfor locking the lock, and the-stamped boss 3| en- The key intended foroperating. the lock is of I gages the window 24 to keep the lever 21firmly in its position.

To open the lock. the key should be turned through a.complete-revolution towards the left. The arm 29 meets successively thebosses IT and I8. The arm 29 is pushed forward by the boss l8 and thelever 21 is brought into the position indicated in chain dotted lines onFig. 2. Should now the key be taken out of the lock, then the latter isin the opened position and the windows 24 and 2-5 are no longerobstructed rbythe arm 30,

this fact indicating that the key has been last used for opening thelock. In this case, the boss which indicates always the accurateposition of I the lock, even in the locks in which two complete turns ofthe key are necessaryior eflecting.

their opening or their locking. i

The signaling device controlled by a helical slot or by a screw-pitchcan be designed" for producing either a translation motion parallel.

to the rotation axis of the key in thelock, or an oscillating motionabout a pin carried by the key and situated atright angles to therotation axis of this latter in the lock.

The extremity '30 of the arm 21 may move with respect to any kind ofreference mark provided onthekey. I g g The device described is only oneexample of embodiment for the subject matter of the present invention.The oscillating lever 21 can, for instance, be replacedby an elementslidinginternally in the recess provided within the key. The indicatingelement can be provided with rei erence marks indicating the opening orlooking o erations of the key. t. What is claimed is: Y 1. Lock and keyindicating mechanism convprising a bell crank lever pivoted in a cavityin the header the key said lever having a longer spring arm extendingsubstantially longitudinally of the key within" said cavity and ashorter rigid arm projecting laterally from the'cavity, means in thelock engaging said shorter arm during operation of the'key said meansmoving said lever to one position when the key is turned in onedirection to lock the lock and to another position tain said spring armresiliently in either of said positions, said positions being visuallyascertainable.

2. Lock and key indicating mechanism comprising a bell crank leverpivoted in a cavity in the head of the key said lever having a longerspring arm extending substantially longitudinally of the key within saidcavity and a shorter rigid arm projecting laterally from the cavity at apoint between the head and the stemof the key, axially spaced means inthe lock located on either side of said projecting arm portion when thekey turned in the opposite direction to open the lock,

and means in said cavity to retain said sprin arm resiliently in eitherof said positions, said positions being visually asceitainablei 3. Lockand'key indicating mechanismcom prising a bell crank lever'pi'votedinacavity in the head of the key said lever having alongsr spring armextending substantially'longitudinally of the key within said cavity anda shorter rigid arm projecting laterally from the cavity, means in thelock engaging said shorter arm-during op eration of the key said meansmoving said lever to one position when the key is turned in onedirection to lock thelock and-to another position when the key is turnedin-the "opposite di rection to open the lock, and means in said =cavityto retain said spring arm resilientlyin'eith'er or said positiona'saidpositions-'beingvisually'ascertainable, said retaining means including abulge on said spring closurably engageable with a window openinginasideof the key head. i

. 4.. Mechanism according .to-claim 2 in which said axially spacedmeansin the lock comprise'a pair of bosses extending radially-or theaxisof the keyhole'of the lock and opposite to each other, eachof'saidbossesvproiectin towards the projecting arm portion, one from:one side and'the other from the other side thereof.

" Gumo HOENGERQ

